Reduction of polyphenol and phytic acid content of pearl millet grains by malting and blanching.

This work was undertaken to evaluate the changes in polyphenol and phytic acid content in malted and blanched pearl millet grains. For malting, grains were steeped for 16 hours, germinated for 48 or 72 hours and then kilned at 50 degrees C for 24 hours. Blanching was done for 30 seconds in boiling water at 98 degrees C. Results indicated that blanching resulted in significant reduction in polyphenol (28%) and phytic acids (38%). Destruction of polyphenols (38 to 48%) and phytic acid (46 to 50%) was significantly higher in grains subjected to malting than blanching: The overall results suggested that malting with 72 hours of germination was most effective in reducing the antinutrient levels of pearl millet grains.     

Sequential fermentation of pearl millet by yeasts and lactobacilli—effect on the antinutrients andin vitro digestibility

Sequential culture fermentation by yeasts (S. diastaticus orS. cerevisiae) at 30°C for 72 hr and then followed by lactobacilli fermentation (L. brevis orL. fermentum) at 30°C for 72 h more resulted in a significant reduction in phytic acid and polyphenol content of pearl millet flour. Fermentation byS. diastaticus andL. brevis combination almost eliminated phytic acid from pearl millet flour. The combinations ofS. diastaticus with both the lactobacilli reduced phytic acid more effectively than those ofS. cerevisiae. The products fermented byS. cerevisiae andL. brevis and byS. diastaticus andL. brevis combinations had the highest protein and starch digestibility (in vitro).     

Levels of antinutritional factors in pearl millet as affected by processing treatments and various types of fermentation

Pearl millet (Pennisetum typhoideum) was fermented with Lactobacilli or yeasts alone and in combination, and with natural microflora after various processing treatments, as grinding, soaking, debranning, dry heat treatment, autoclaving and germination. Fermentation was carried out at 30°C for 48 hours withLactobacillus plantarum (LP) andRhodotorula (R) isolated from naturally fermented pearl millet andLactobacillus acidophilus (LA),Candida utilis (CU) and natural microflora (NF). Germination and autoclaving, and debranning and autoclaving were the most effective processing treatments to reduce the phytic acid, amylase inhibitors and polyphenols. There was a further reduction in these antinutrients due to fermentation. Phytic acid and amylase inhibitors were completely eliminated after fermentation in some of the samples especially in soaked, debranned and germinated ones. Polyphenols were altered non-significantly in general but fermentation with Lp+R and NF caused a significant increased in polyphenols.     

Investigations into the thiamine and riboflavin content of malt and the effects of malting and roasting on their final content

A simple and effective method for the analysis of thiamine (B₁) and riboflavin (B₂) vitamers, in unmalted and malted grains, by high performance liquid chromatography (HPLC) has been developed. This method makes use of trichloroacetic acid (TCA) as an extraction medium to effectively clean up the sample and analyze the vitamer content with high accuracy (R² > 0.9992; %RSD < 5%). This method was employed in the routine analysis of a wide range of malted and unmalted grains, and it was found that lighter colored malts contain higher concentrations (2–5 times higher) of thiamine and riboflavin vitamers compared to darker colored malts. The malting process has no effect on the overall riboflavin content; however, both steeping and kilning processes cause increases in thiamine vitamer content. Roasting profiles show that thiamine and riboflavin vitamer concentrations are significantly effected when the temperature reaches 120 °C, which explains why roasted products have lower vitamer content than paler malts.     

Effect of fermentation on protein,fat, minerals and thiamine content of pearl millet

Natural as well as single, mixed and sequential pure cutlure (S. diastaticus, S. cerevisiae, L. brevis andL. fermentum) fermentations of pearl millet flour for 72h lowered pH and raised titratable acidity. The fermentation either decreased or did not change the protein content of pearl millet flour. Natural fermentation increased whereas pure culture fermentation decreased the fat content. Ash content did not change. Natural fermentation at 20°C and 25°C increased whereas at 30°C it decreased the thiamine content of the pearl millet flour. Yeast fermentation raised the level of thiamine two- to three-fold, while lactobacilli fermentation lowered it significantly.     

Effects of cooking,germination and fermentation on the chemical composition of Nigerian Cowpea (Vigna unguiculata)

The effects of cooking, germination, and fermentation on the chemical composition of cowpea were studied. There were noticeable trends in the protein, carbohydrate and crude fiber as a result of the different treatments. Both the germinated and fermented samples contained more ether extractable lipids than the raw and cooked samples. Untreated raw cowpea contained 5.9 mg/g phytic acid, 1.66 mg/g phytate phosphorus, 3.3 mg/g total phosphorus, 56.8 mg/g total sugar, and no reducing sugar. Cooking the dry beans at 100°C for 1 1/2 hours had little effect on the phytic acid and phytate phosphorus. There were, however, significant decreases in total phosphorus and sugars of the cooked beans. After germination for 24 hours, 48 hours and 72 hours respectively, there was a significant decrease in phytic acid and total sugar and increase in total phosphorus and reducing sugar. Similar results were also obtained when the dry beans was fermented for 24 hours, 48 hours and 72 hours respectively.     

Effects of seed treatments and storage on the changes in lipids of pearl millet meal

Lipids in pearl millet meal showed a rapid hydrolytic decomposition during storage. The magnitude of such degradation was influenced significantly by the nature of the storage container used, the temperature and heat treatments given to the seeds. The hydrolytic breakdown of lipids was significantly low in the meals stored in polyethylene bags, plastic boxes and under refrigerated (5±2 °C) conditions. Hot water blanching at 98 °C for 10 sec and dry heating of seeds at 100 °C for 120 min were found to be most effective in minimising the undesirable changes in lipids of the meal during storage.     

Development,nutritive content and shelf life of home processed supplementary foods

Four low cost supplements containing whole wheat, pearl millet, bengal gram, green gram grain and amaranth leaves employing roasting and malting methods were developed. Nutritional evaluation showed that chemical composition of developed supplements was within the range prescribed for processed supplements and could meet satisfactorily one third requirements of protein, energy, iron and calcium for young children. Developed supplements were stored in three packings, polythene bags, tins with lids, glass bottle with lids (each 1 kg capacity, under ambient temperature (24–32°C) and RH (70–80%) for a period of 30 days and analysed for moisture, peroxide value, fat acidity and alcoholic acidity. Stored samples were also evaluated organoleptically. The values of moisture, peroxide value, fat acidity and alcoholic acidity of stored samples were within the range of prescribed specifications for processed supplements. Storage of supplements for 30 days resulted in non-significant changes in organoleptic traits except for taste and aroma of bajra based supplements on 20th and 30th day of storage. In spite of these variations, all the supplements were found to be acceptable till 30th day of storage.     

Tolerance of foxtail,proso and pearl millets to saflufenacil

Herbicide options for weed control in millets are very limited and hence there is a need for exploring potential herbicides. Field trials were conducted at three locations in Kansas and Nebraska in 2009 to evaluate foxtail millet, proso millet, and pearl millet tolerance to saflufenacil applied preemergence (PRE) at 36, 50, and 100 g ai ha⁻¹. Foxtail millet was the most sensitive of the three millets to saflufenacil. Among experimental sites, saflufenacil at 36 g ha⁻¹ injured foxtail millet 59–99% and reduced plant stands 41–95%; nearly all plants died at 100 g ha⁻¹. Despite early season foliar injury and up to 36% stand reduction, fodder or grain yields of proso and pearl millets were not reduced by any rate of saflufenacil compared to untreated controls. Additional trials were conducted at four locations in Kansas, Nebraska and South Dakota in 2010 and 2011 to refine saflufenacil use rate (36 and 50 g ha⁻¹) and application timing [14 days early preplant (EPP); 7 days preplant (PP); and PRE] for use in proso and pearl millets. Saflufenacil applied EPP or PP, regardless of rate, caused up to 21 and 6% foliar injury and up to 21 and 9% plant stand reduction in proso and pearl millets, respectively. However, yields were not reduced by EPP or PP treatments in either millet crop. PRE applications of saflufenacil caused the highest crop injury and stand reduction in both millets. Saflufenacil PRE at 36 g ha⁻¹ caused up to 57 and 40% foliar injury and up to 42 and 24% stand reductions in proso and pearl millets, respectively; however, yields were not affected. Comparatively, saflufenacil PRE at 50 g ha⁻¹ reduced yields of proso and pearl millets 36 and 52%, respectively, on sandy loam soils with high pH (8.3) and low organic matter content (1.1%). Overall, results indicated that foxtail millet lacks tolerance to saflufenacil, but up to 50 g ha⁻¹ of saflufenacil may be safely applied as near as 7 days before planting proso or pearl millets. If situation demands, saflufenacil at 36 g ha⁻¹ can also be applied PRE to either crop with risk of some crop injury.     

Effects of malting on the milling performance and acceptability of bambara groundnut (Voandzeia subterranea Thouars) seeds and products

Germinated bambara groundnut was dried by three methods – oven-drying at 50 °C, in a solar drier at 38–42 °C, and sun drying at 28 ± 2 °C. The samples were milled into flour, and made into okpa, a steamed gel. Flour yield increased only in oven-dried malts. The quality of the okpa based on appearance and taste decreased with malting time; solar drying resulted in the poorest product because of its dark color.     

Chemical composition and nutrient digestibility of pearl millet (Pennisetum glaucum) fed to growing pigs

Pearl millet grown at two different locations in the U.S.A., pearl millet A (PMA) and pearl millet B (PMB), were analyzed for chemical composition and nutrient content and compared to corn. The two samples of pearl millet and corn were incorporated into diets and fed to 24 growing pigs in a metabolism trial to determine nitrogen and mineral balance and digestibilities of energy, fat and amino acids. Pearl millet (PMA and PMB) was found to be richer in crude protein, gross energy, ether extract, acid detergent fiber, amino acid profile and mineral content than corn. However, digestibilities of dry matter (corn, 86·8%; PMA, 80·5%; PMB, 82·0%) and energy (corn, 85·3%; PMA, 78·8%; PMB, 80·5%) were higher (P<0·05) for corn than either of the pearl millet samples. Fat digestibility was much higher in pearl millet than corn. Although nitrogen intake and absorption were higher (P<0·05) for pearl millet, the digestibility of nitrogen was similar for pearl millet and corn. Net protein utilization was lower (P<0·05) in pearl millet when compared to corn (corn, 44·8%; PMA, 34·6%; PMB, 39·9%). Digestibilities of the essential amino acids, arginine, threonine, valine, isoleucine and lysine were higher in pearl millet than corn. Phosphorus retention, expressed as a percentage of intake and absorption, was higher in corn than pearl millet. Calcium intake and absorption were similar for pearl millet and corn. Intake and absorption of magnesium and managanese were also similar in pearl millet and corn. Zinc and copper retention, when expressed as a percentage of intake, were higher in corn, but absorption for both minerals was similar in corn and pearl millet. Pearl millet was found to supersede corn in nutrient content and amino acid digestibility.     

Nutritional quality of pearl millet flour and bread

Market samples of pearl millet flour and bread from Saudi Arabia were analysed for chemical composition and nutritional quality. Pearl millet flour contained, on a dry weight basis, 17.4% protein, 6.3% fat, 2.8% fiber and 2.2% ash. Lysine was the most limiting essential amino acid with a chemical score of 53 (FAO/WHO, 1973). Linoleic acid (44.8%), oleic acid (23.2%) and palmitic acid (22.3%) were the dominant fatty acids in millet oil followed by stearic acid (4.0%) and linolenic acid (2.9%). The invitro protein digestibility (IVPD) of millet flour was 75.6% and the calculated protein efficiency ratio (C-PER) was 1.38 in comparison to ANRC casein values of 90% and 2.50, respectively. Baking at 300°C for 15 min had only little effect on the proximate and fatty acid composition of the bread but decreased the arginine, cystine and lysine contents by 31.3%, 15.8% and 13.8%, respectively. The IVPD was not affected but the C-PER decreased by 18% on baking.     

Optimization of the solid state fermentation process to obtain tempeh from hardened chickpeas (Cicer arietinum L.)

Solid state fermentation (SSF) represents a technological alternative for a great variety of cereals and legumes, orcombination of them, to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The objective of this work was to find the best conditions of fermentation temperature and time to obtain tempeh from hardened chickpeas (Cicer arietinum L.) applying SSF. Response surface methodology(RSM) was applied over three response variables (phytic acid, in vitro protein digestibility and available lysine) to find best conditions of fermentation to carry out the process. A central composite experimental design with two factors [X₁ = temperature (31–36 ^°C) and X₂ = time (48–72 h)] in five levels (2 factorials,2 axial, I central) was used. Spores from Rhizopus stolonifer were suspended in distilled water (1 ×10⁶ spores/mL) and used as starter. According to regression models, minimum and maximum levels of the response variables were 1.24–2.66 mg phytic acid/g ofsample DM, 77.6–83.5% in vitro protein digestibility and2.18–4.63 g available lysine/16 g N. The superposition ofcontour plots of each one of the response variables allowedresearchers to find, graphically, the best conditions for the SSF process: 35.8 ^°C for 42.7 h.     

Influence of sulphur application on hordein composition and malting quality of barley (Hordeum vulgare L.) in northern European growing conditions

The influence of sulphur (S) application on yield formation, hordein composition and malting quality of 2-rowed spring barley (Hordeum vulgare L.) was studied in Nordic conditions for the first time. In a greenhouse experiment, S deficiency was indicated when 10 mg S/kg soil or less was available, by an increase in the malate:sulphate ratio in leaves. The contents of aspartic acid and cystine in grains increased and decreased, respectively. Also a substantial decrease of total hordein and the proportion of B hordein, and an increase in the proportion of C hordein were associated with S deficiency. The effect of S was further assessed in field experiments by applying N and S in four different combinations prior to sowing. No apparent S deficiency occurred in the field conditions based on the malate:sulphate and grain N:S ratio. However, in a site where the grain S content was slightly but significantly increased by S application, a change in hordein composition and malting quality was observed. Thus even in S-sufficient conditions, the end use quality of malting barley may be affected by S application.     

Elaboration of amylase activity and changes in paste viscosity of some common Indian legumes during germination

The effect of germination upto 120 hours on malting loss, amylase activity and viscosity of nine common Indian legumes was investigated. The amylase activity increased on progressive germination in all legumes, the increase being particularly high for green gram, horse gram, moth bean and black gram. Malted samples had lower cooked paste viscosity than native ones. Samples with high amylase activity exhibited proportionately lower viscosity. Maximum reduction in viscosity was observed in green gram, followed by moth bean, horse gram, black gram and cowpea within 48 hours of germination. Malting losses ranged between 12 to 27 percent over a period of 48 hours in all legumes. Germination beyond 48 hours resulted in considerably higher malting losses without much effect on viscosity.     

Influence of particle size and blend composition on quality of wheat semolina-pearl millet pasta

Effect of particle size and blend composition (wheat semolina: pearl millet flour) on quality of pasta were investigated in this study. Initially, the pasta was prepared from 100% pearl millet flour of different particle sizes (241–780 μm). Observation indicated that it was not possible to make pasta from 100% pearl millet flour as these disintegrated after cooking. Particle sizes of pearl millet flour showed significant effect on nutritional and cooking quality of pearl millet pasta. Pasta from pearl millet flour of particle size 425 μm had least cooking loss, high protein, iron and zinc contents. Further, with increase in the level of pearl millet flour in the blend composition, protein, ash and cooking loss of pasta increased whereas hardness, cohesiveness, springiness, gumminess and chewiness showed decreasing trend. Blend composition (wheat semolina: pearl millet flour) in the ratio of 70:30 was found to be satisfactory for making pasta with desirable quality characteristics like cooking loss (<8%), protein content (>10%), ash content (<0.7%), colour and texture. However, with the objective of maximum incorporation of pearl millet flour in the final product, a blend composition of 50:50 could be used to make pasta with acceptable quality.     

Antinutrients in amphidiploids (black gram × mung bean): varietal differences and effect of domestic processing and cooking

Phytic acid, saponin and polyphenol contents in grains of various varieties of black gram (Vigna mungo) Mung bean (Vigna radiata L.) amphidiploids ranged from 697 to 750, 2746 to 2972 and 702 to 783 mg/100 g, respectively. Domestic processing and cooking methods including soaking, ordinary and pressure cooking of soaked and unsoaked seeds, and sprouting significantly lowered phytic acid, saponin and polyphenol contents of the amphidiploid seeds. Soaking for 18 h removed 31 to 37% of the phytic acid; the extent of removal was higher with long periods of soaking. Saponins and polyphenols were relatively less affected. Loss of the antinutrients was greater when soaked instead of unsoaked seeds were cooked. Pressure cooking had a greater effect than ordinary cooking. Antinutrient concentrations declined following sprouting; the longer the period of germination the greater was the reduction.     

Effect of processing on protein digestibility,biological value and net protein utilization of millet and legume based infant mixes and biscuits

Effect of combinations of millet and legume and processing on digestibility, biological value and net protein utilization was evaluated using albino rats. The millets and legumes selected for the study include sorghum, pearl millet, finger millet, chickpea and green gram (P radiatus). The processes tested include dehulling, boiling, roasting, malting and baking. Among the combinations tested, the sorghum-chickpea combination had significantly (p<0.05) higher digestibility. Between the processes tested, roasting resulted in significantly higher net protein utilization. Results of biological study on biscuits prepared by using millet and legume combination flours, indicated the biscuits to be of good protein quality.     

Acceptability and viscosity of low cost home processed supplementary foods developed for pre-school children

Four supplement mixtures using whole wheat, pearl millet, bengal gram, green gram, groundnuts and amaranth leaves were developed employing roasting and malting techniques. Malting used in the formation of the supplements reduced significantly hot paste viscosity of all the four supplements and increased their nutrient density per unit volume. The results of organoleptic trials conducted on rural mothers revealed that taste, texture, colour, aroma, appearance and overall acceptability of all the four supplements were excellent with mean scores of overall acceptability (9.77, 9.33, 9.11 and 8.75) for supplements I, II, III and IV, respectively. Children did not develop any GIT disorders after consuming the products. Trained panelists found all the four supplements acceptable as indicated by Nine point hedonic scale.     

Acceptability and viscosity of low cost home processed supplementary foods developed for preschool children

Four supplement mixtures using whole wheat, pearl millet, bengal gram, green gram, groundnuts and amaranth leaves were developed employing roasting and malting techniques. Malting used in the formation of the supplements reduced significantly hot paste viscosity of all the four supplements and increased their nutrient density per unit volume. The organoleptic trials conducted on rural mothers revealed that taste, texture, colour, aroma, appearance and overall acceptability of all the four supplements were found to be excellent with mean overall acceptability. Children did not develop any GIT disorders after consuming the products. Trained panelists found all the four supplements acceptable as indicated by a nine point hedonic scale.